Alone

In Tokyo,Japan an evil organization known as the Korosu has a plan to take over the government. They're leader, Hato Zetsubo will take down any, and everyone that steps in his way, to get to his goal.
The Korosu take in innocent young boys and girls from their families, and inject them with a potassium know as "Terutera". Once injected
the children ate turned into mindless killing machines.
The children are kept in cells,and are locked away and sometimes even beat. The children are also taught how to kill. One boy escapes, his name is Hitori Kanashimi. After leaving and regaining his memory, Hitori refuses to make friends in fear of hurting them. Hitori ends up meeting a girl named Taizai and a boy named Tasukete.They end up becoming friends,and work together to take down the Korosu.